The stand-up paddle boards referenced herein are generally small, human-powered boats that are traditionally rowed over a body of water while the rider stands upon the board. Many inflatable boards, including surfboards and stand-up paddle boards made with drop-stitch construction are generally flat because the flat structure is more easily constructed than a contoured surface. However, a flat board moves less efficiently through the water. Also, many paddle boards do not have a displacement hull. Drop-stitch construction is a process for forming inflatable structures that are very durable and rigid when inflated. A typical drop-stitch construction involves joining two generally parallel, usually flat sheets of material with hundreds or thousands of thin threads between the sheets. Sidewalls can be attached to seal the interior of the structure, which can then be inflated. Conventional inflatable paddle boards and surfboards made from drop-stitch construction are flat or have a slight unidirectional contour.
A flat construction for inflatable paddle boards, where the top and bottom walls of the drop-stitch construction are generally parallel with each other and with the water surface, is relatively inexpensive to manufacture and are easily portable. However, these boards sacrifice movement efficiency. There is a need for a board that is easily constructed, easily portable, and that has excellent hydrodynamic qualities.
An example of a boat made using drop stitch techniques is shown in U.S. Pat. No. 7,861,662 to Rista. Rista is directed to a boat made of upper and lower fabric layers and also a core section made up in an array of threads extending throughout the drop stitch structure, and sidewalls enclosing the drop stitch structure. However, the boats disclosed by Rista do not have displacement hulls and therefore are less efficient than other watercraft having a displacement hull.